This invention is related to commonly assigned and co-pending U.S. patent application corresponding to attorney docket No. H-196872.
Conventional cruise control systems control vehicle speed to an operator set speed. Adaptive cruise control systems are known which have varying degrees of interaction with preceding vehicles. A general objective of adaptive cruise control systems is to sense in-path objects such as preceding vehicles and to provide throttle control to maintain a predetermined distance therefrom. Such base systems are characterized by passive deceleration, that is to say deceleration effectuated during closed-throttle coast.
An exemplary adaptive cruise control system employing active vehicle deceleration, that is to say deceleration effectuated by active, controlled application of the vehicle service brakes, is disclosed in U.S. Pat. No. 5,173,859 to Deering, hereafter "Deering", also assigned to the assignee of the present invention. Deering describes a system wherein vehicle braking control is invoked to decelerate a succeeding vehicle when the succeeding vehicle violates a predetermined range from the preceding vehicle with a range rate indicating that the succeeding vehicle is closing on a preceding vehicle. Such is generally experienced when the preceding vehicle undergoes deceleration due to service brake application.
Vehicle cut-ins, that is to say introduction of a new preceding vehicle in a succeeding vehicle's pathway, commonly occur while operating a vehicle on multi-lane roadways. Cut-ins are operating situations generally characterized by one vehicle changing lanes in front of and/or behind another vehicle. The vehicle changing lanes may affect the operation of an adaptive cruise control system of a vehicle behind itself or, in the case where the vehicle changing lanes is equipped with an adaptive cruise control system, may have its operation affected by the lane change. This is particularly true where the inter-vehicle spacing between the preceding and succeeding vehicles subsequent to the lane change is relatively small. Such cut-ins may result in aggressive active deceleration of the succeeding vehicle based upon violation of inter-vehicle spacing objectives of the system. However, cut-ins are frequently characterized by the lane changing vehicle having a nearly equivalent speed as the adjacent lane vehicle(s). Hence, active deceleration of the succeeding vehicle may be too aggressive for cut-ins characterized by a relatively minor speed differential between the preceding and succeeding vehicles subsequent to the cut-in maneuver.